This application is related to and claims priority from Japanese Patent Applications No. Hei. 11-92129 filed on Mar. 31, 1999, No. Hei. 11-274729 filed on Sep. 28, 1999, and No. 2000-17821 filed on Jan. 21, 2000, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a link lever system which operates a single output lever by plural input levers manually operated, and relates to a vehicle air conditioner using the link lever system.
2. Description of Related Art
In a conventional vehicle air conditioner, for improving both heating performance for a lower side of a passenger compartment and defrosting performance of a windshield in the winter, an inside/outside air double layer flow mode (hereinafter, referred to as xe2x80x9cdouble layer flow modexe2x80x9d) is set so that inside air having a high temperature is blown from a foot opening and outside air having a low humidity is blown from a defroster opening. Further, the double layer flow mode is set when a maximum heating is set. Thus, it is necessary to set the double layer flow mode based on both operation conditions of an air outlet mode and a temperature adjustment unit. In the conventional air conditioner, an electronic control unit for determining a set condition of the double layer flow mode and a door driving motor for electrically controlling plural doors are provided, and the double layer flow mode is set by the door driving motor based on control signals of the electronic control unit. Thus, production cost of the vehicle air conditioner is increased.
In view of the foregoing problems, it is an object of the present invention to provide a link lever system which operates an output lever at a predetermined position when operation positions of plural input levers satisfy a predetermined condition.
It is an another object of the present invention to provide a vehicle air conditioner which can readily manually set a double layer flow mode.
According to a first aspect of the present invention, a link lever system includes a plurality of input levers which are respectively manually operated, an output lever operatively linked with the input levers, and a driven member connected to the output lever to be operated by the output lever. In the link lever system, the output lever is operated to a first predetermined position, when the input levers are operated to set operation positions satisfying a predetermined condition. Thus, the output lever is accurately displaced in accordance with displaced operation positions of the input levers.
Preferably, the output lever is operated to a second predetermined position while a displacement of the output lever due to an elastic force of an elastic member is prevented by first engagement means between a first input lever of the plural input levers and the output lever, when the first input lever is operated at an operation position different from the set operation position of the predetermined condition. Therefore, the output lever is accurately displaced to the first or second predetermined position in accordance with the operation positions of the input levers.
Further, the output lever is operated to the second predetermined position while a displacement of the output lever due to the elastic force of the elastic member is prevented by second engagement means between a second input lever of the plural input levers and the output lever, when the second input lever is operated at an operation position different from the set operation position of the predetermined condition. Therefore, when the second input lever is operated to a position different from the set operation position of the predetermined condition, the output lever is accurately maintained at the second predetermined position by the second engagement means regardless of the operation position of the first input lever.
Preferably, the link lever system is provided in a vehicle air conditioner including an air conditioning case for defining an air passage through which air flows into a passenger compartment, an inside/outside air switching door for switching inside air and outside air to be introduced into the air conditioning case, a mode operation member provided on an operation panel of the passenger compartment to be manually operated through which an air outlet mode for selecting an air flow direction in the passenger compartment is set, and a temperature-adjustment operation member provided on the operation panel to be manually operated through which temperature of air blown into the passenger compartment is adjusted. The first input lever of the link lever system is operatively linked with the mode operation member, the second input lever is operatively linked with the temperature-adjustment operation member, and the output lever operatively connected to the inside/outside air switching door is operated by operating the first and second input levers at operation positions. Thus, the inside/outside air switching door is operated to be switched in accordance with a manual set position of the mode operation member and a manual set position of the temperature-adjustment operation member.
According to a second aspect of the present invention, an air conditioner for a vehicle includes a case having a first opening through which air is blown toward a windshield and a second opening through which air is blown toward a lower side of a passenger compartment, a partition member for partitioning an air passage of the case into a first air passage communicating with the first opening and a second air passage communicating with the second opening during a double layer flow mode, a first inside/outside air switching door for switching inside air and outside air to be introduced into the first air passage, a second inside/outside air switching door for switching inside air and outside air to be introduced into the second air passage, a first door lever operatively connected to the first inside/outside air switching door, a second door lever operatively connected to the second inside/outside air switching door, an inside/outside air operation member disposed on an operation panel of the passenger compartment to be manually operated for switching inside air and outside air to be introduced, a mode operation member disposed on the operation panel to be manually operated for switching an air outlet mode for setting an air flow direction in the passenger compartment, a mode operation lever operatively linked with the mode operation member, a temperature-adjustment operation member disposed on the operation panel to be manually operated for adjusting temperature of air blown into the passenger compartment, and a temperature-adjustment operation lever operatively linked with the temperature-adjustment operation member. The first inside/outside air switching door is driven to be opened and closed based on a manual operation of the inside/outside air operation member through the first door lever, and the second door lever is operated through the mode operation lever and the temperature-adjustment operation lever based on manual operations of the mode operation member and the temperature-adjustment operation member, to operate the second inside/outside air switching door. Thus, it is possible to set the first door lever at an outside air introduction position of the first inside/outside air switching door by a manual operation of the inside/outside air operation member, while it is possible to set the second door lever at an inside air introduction position of the second inside/outside air switching door by combining manual operations of the mode operation member and the temperature-adjustment operation member through the mode operation lever and the temperature-adjustment operation lever. As a result, in the vehicle air conditioner, a double layer flow mode is readily manually set.
According to a third aspect of the present invention, a vehicle air conditioner includes an inside/outside air switching door for switching inside air and outside air to be introduced into an air passage, an inside/outside air operation member disposed on an operation panel of the passenger compartment to be manually operated for switching inside air and outside air to be introduced into the air passage, a mode operation member disposed on the operation panel to be manually operated for switching an air outlet mode for setting an air flow direction in the passenger compartment, a mode operation lever operatively linked with the mode operation member, an input door lever operatively linked with the inside/outside air operation member, and an output door lever connected to the inside/outside air switching door. The output door lever is disposed to be operated based on operation positions of the mode operation lever and the input door lever. In the vehicle air conditioner, when a defroster main mode where air more than a predetermined amount is blown from the defroster opening is manually set by the mode operation member, the output door lever is maintained by the mode operation lever to an outside air introduction position of the inside/outside air switching door, where only outside air is introduced into the air passage. On the other hand, when an air outlet mode except for the defroster main mode is manually set by the mode operation member, the output door lever is operated by the input door lever to set an air introduction mode which is set manually by the inside/outside air operation member. As a result, during the defroster main mode, even when an inside air mode is manually set by mistake by a passenger, an outside air introduction is forcibly set with the setting operation of the defroster main mode, and defrosting performance of a windshield is improved.